Ask the Doctors

Dear Doctor: My husband, who plays in a weekend soccer league, is troubled by some new reports he has read that suggest that soccer might be as dangerous as football. Can you explain the studies?

Dear Reader: Your husband may be referring to a pair of studies published in February that examined the potential risks of heading the ball, a common move in soccer. One study, conducted at a British university, found signs of brain damage in a group of professional soccer players, all of whom had decades-long careers. The other study, published by researchers at Albert Einstein College of Medicine in New York, focused on amateur players. The study found an increased risk of concussion both from heading the ball and from accidental contact during a game.

But before you insist that your husband turns in his cleats, let's take a closer look at the data.

The British study examined 14 retired soccer players with dementia. The men, skilled at heading the ball, played for an average of 26 years each. When the brain tissue of six of the players was examined after their death, researchers found signs of trauma.

In four of the six brains, this included chronic traumatic encephalopathy (CTE), a progressive degenerative disease also found in professional boxers, football players and hockey players. Although the small sample size of the British study kept researchers from drawing conclusions, they agreed the results reveal the need for large-scale studies.

In the American study, researchers followed 222 amateur soccer players, both men and women. Players reported how often they headed the ball, as well as any accidental blows to the head during play. They also rated the severity of symptoms like headache, dizziness, altered vision, weakness or confusion, which can indicate concussion.

The researchers concluded that while heading the ball increased a player's risk of concussive impact, accidental contact, like an elbow to the head or colliding with another player, was even more common.

Research into sports-related concussions has previously focused on football and hockey, where bruising impacts are part of the game. Now, scientists are expanding their inquiries into soccer.

Soccer is the world's most popular team sport. It is estimated that amateur players head the ball up to 12 times per game. Add in practice drills, and this can add up to 2,000 headers over 20 years. The question now is whether the effect of all those headers on the delicate structures of the brain can be cumulative.

For the authors of the American study, the answer was yes. They recommend that players be aware of any concussion symptoms, even absent a conclusive concussion diagnosis. Should symptoms appear, players must avoid another collision in the following weeks, when the risk of another concussion spikes significantly.

The truth is, all physical activity carries both risks and benefits. One thing we discuss with our patients regarding soccer is the risk of knee injury, given the high lateral impact forces.

It sounds as though your husband is staying abreast of the latest research, which is wise. He can use it to decide how -- and even whether -- he decides to play soccer in the future.